Huynh T, et al. - In the TOPCAT study involving patients with heart failure and preserved left ventricular ejection fraction, researchers determined how clinical outcomes in this patient population were impacted by diabetes mellitus (DM) status and insulin treatment. Time to development of a composite of cardiovascular (CV) mortality, heart failure hospitalization, and aborted cardiac arrest (primary end point) were assessed in relation to DM status (insulin-treated [ITDM], non-insulin treated [NITDM], and no diabetes [non-DM]) at baseline. The investigators analyses were restricted on findings from patients enrolled from the Americas. Nearly twofold increased risk for the primary end point, heart failure hospitalization, and myocardial infarction, as well as nearly 50% increases in all-cause and CV mortality were observed in patients with ITDM vs patients without DM. Patients with ITDM also had increased risks for these outcomes vs patients with NITDM. For the primary end point and all secondary end points, patients with NITDM vs those without DM had similar risks.